Okay so my phone just updated and now I have this new icon with a text message icon next too it. When I used it to make phone calls earlier, I wasnt able to merge calls. What is this?
Real-time text (RTT)
You can view this feature in settings>accessibility>hearing enhancements>real time text>always viable
It also available in by pressing the (3 dots) while in a call if you have that feature turned off.
The text that you enter appears to the other person in real time, unlike with chat messaging. For example, if you make a mistake and then delete it, the other person can see the mistake and the deletion.
For more detailed information you can use this link to learn about the rtt calls:
Hope this helps you understand this new button.